Electromagnetic driving direction indicator



March 24, 1931' v F E A 1,797,885

ELECTROMAGNETIC DRIVING DIRECTION INDICATOR Filed March 14. 1929Patented Mar. 24, 193T UNITED. STATES PATENT OFFICE ELECTROMAGNETICDRIVING DIRECTION INDICATOR Application filed limb 14, 1929, Serial No.

Electro-magnetic driving direction indicators can be divided into twomain types, that is, the so-called drum indicators in which a disc isrotated by means of an electro- 6 magnetic yoke, so that the drivingdirection may be indicated by the position of said disc; and theso-called Winkers angle arm indicators in which an indicator arm ismoved by the electro-magnet from its normal vertical 10 position into anupright indicating position.

The last mentioned type ofindlcator possesses the advantage that whentheangle arm is in the indicating position the contour of the instrument isaltered, so that it is 1 more clearly visible, and consequently complieswith many oflicial regulations for public trafiic vehicles that onlysuch indicators are to be'used.

The resent invention relates to such an angle indicator. In the hithertoknown forms of construction there is always a firm connection, arrangeddirectly or indirectly, between the angle arm and the magnet coreactuated by the solenoid. As however in-order to, avoid having a deadpoint, the axis of the point of attachment cannot lie in a verticalplane with the axis of rotation of the angle arm, but must be shifted alittle to one side, the magnet core describing a double curve.

lating coil, or one of special construction. The first mentioned form ofconstruction takes up a comparatively large amount of room, and alsonecessitates movable wire con nections, whilst the last mentioned formis comparatively expensive in construction. Furthermore all thesemovable connections and arrangements are uncertain in action, as byinappreciable alterations in the shape, or 40 by the collection of dirtthereon, resistances are created, which the battery, always giving onlya small current, is unable to. overcome.

A further defect of these angle arms consists in the fact that they areeasily moved out of the normal vertical osition by the vi bration of thevehicle and cation. This defect can only be remedied by springs orcontrol magnets in a complicated This necessltates the use of an 0scil--in this way' also give rise to uncertain action or faulty 1nd1-indicator comprising a pivoted indicator arm 346,912, and in GermanyMarch 2a, 1928.

manner and even then the defect could not be surmounted with certainty.I

The present invention overcomes all these defects, whilst at the sametime simplifying the construction of the part controlling the angle arm.The main characteristic of the invention consists in that. the actuatingslot through which the magnet core engages the angle arm, is providedwith a cut-out part which rests on the actuating pin ofthe arm in thenormal position of the angle arm, so that the weight of the magnet' coreholds the angle arm in the normal position, and in the simplest possiblemanner.

The accompanying drawing shows as an example a form of construction ofsuch an arrangement in a driving direction indicator in Fig. 1 in thenormal position and in Fig. 2 in the working position.

The angle arm top a is provided with a simple or hook shaped stud, orso-called carryingpin 6, whose curving movement is taken up by the slot0 of the-free magnet core (1 freely moving without any point ofattachment in the magnet coil 8. A cut-out part 2' sur- 5 rounds the pin7; of the indicator arm at its drop into the normal position, andretains it in this position until current is switched on and raises themagnet core up from the pin. In orderrto reduce friction a frictionroller can be fitted on the pin b. Thecasing -g surrounds thearrangement.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is 1. -An electromagnetic driving direction indicatorcomprising a movable pivoted indicator arm having a projection offsetfrom'the pivot, a core arranged above said arm and 7. having an openslot to receive said projec- .tion, said core fitting snugly in the coilof a solenoid the upper wall of said slot comprising a seat adapted tocooperate with said pro 5- jection and to support the core upon saidproectlon, whereby to maintain the arm in its downward position by theweight of the core. 2. In an electromagnetic driving direction having aprojecting pin in proximity to and spaced from the point where the armis pivoted, a core arranged above said arm and having a slot receivinsaid pin, said core fittin snugly in the coil of a solenoid, and a seatdefining part of the slot adapted to cooperate with the pin and supportthe core upon the pin, whereby to maintain the arm in one position bythe weight of the core.

In testimony that I claim the foregoing as my invention, I have signedmy name hereto.

FRIEDRICH KARL TEICHGRBER.

